For example, in the case where a packet mirrored by a switch device is transferred to a diagnosing device, and a communication state of a system is diagnosed, bandwidth control may be executed by the switch device based on a communication load in a network.
In the bandwidth control, the packet is temporarily stored in a buffer and output while a bandwidth to be used is suppressed. When the total amount of stored packets increases and exceeds the capacity of the buffer, a packet mirrored after that is randomly lost.
There is an important index to be used for the diagnosing device to accurately diagnose the communication state of the system. For example, like the Transmission Control Protocol (TCP), in a system for communicating data on the premise of a connected state, a connection period is a basic index. The connection period is used for the calculation of an average connection period or the amount of data to be transmitted per connection.
Examples of related art are Japanese Laid-open Patent Publication No. 2002-281086, Japanese Laid-open Patent Publication No. 2008-085694, and Japanese Laid-open Patent Publication No. 2012-004781.